When it comes to income tax returns, April 15 (actually April 17 this year, because of a weekend and a Washington, D.C., holiday) isn’t the only deadline taxpayers need to think about. The federal income tax filing deadline for calendar-year partnerships, S corporations and limited liability companies (LLCs) treated as partnerships or S corporations for tax purposes is March 15. While this has been the S corporation deadline for a long time, it’s only the second year the partnership deadline has been in March rather than in April.

Why the deadline change?

One of the primary reasons for moving up the partnership filing deadline was to make it easier for owners to file their personal returns by the April filing deadline. After all, partnership (and S corporation) income passes through to the owners. The earlier date allows owners to use the information contained in the pass-through entity forms to file their personal returns.

What about fiscal-year entities?

For partnerships with fiscal year ends, tax returns are now due the 15th day of the third month after the close of the tax year. The same deadline applies to fiscal-year S corporations. Under prior law, returns for fiscal-year partnerships were due the 15th day of the fourth month after the close of the fiscal tax year.

What about extensions?

If you haven’t filed your calendar-year partnership or S corporation return yet, you may be thinking about an extension. Under the current law, the maximum extension for calendar-year partnerships is six months (until September 17, 2018, for 2017 returns). This is up from five months under prior law. So the extension deadline is the same — only the length of the extension has changed. The extension deadline for calendar-year S corporations also is September 17, 2018, for 2017 returns.

Whether you’ll be filing a partnership or an S corporation return, you must file for the extension by March 15 if it’s a calendar-year entity.

When does an extension make sense?

Filing for an extension can be tax-smart if you’re missing critical documents or you face unexpected life events that prevent you from devoting sufficient time to your return right now.

But keep in mind that, to avoid potential interest and penalties, you still must (with a few exceptions) pay any tax due by the unextended deadline. There may not be any tax liability from the partnership or S corporation return. If, however, filing for an extension for the entity return causes you to also have to file an extension for your personal return, you need to keep this in mind related to the individual tax return April 17 deadline.

Have more questions about the filing deadlines that apply to you or avoiding interest and penalties? Contact us.

© 2018


Hugh Hermanek provides tax planning and preparation services for individuals and businesses.  He has extensive experience in small business and accounting software consulting and advises clients on how to create efficiencies using technology.  Hugh’s understanding of technology and internal control processes are also used in performing SOC examinations.
Prior to joining Hancock & Dana in 1999, he worked for ten years in private industry for two different Midwestern retailers.